To resist sugar's siren song, sleep a little longer every night

A bit of sugar is not a bad thing. But too many of us eat too much of it — unable to resist its sweet allure. (Confession: I ate two-thirds of a pack of Tim Tams in a single sitting last week, so I get it.)

New research from King’s College London (KCL) suggests a simple shield against sugar: sleep.

The study, published in The American Journal of Clinical Nutrition, gathered 42 healthy people who habitually slept between five and seven hours per night — under the seven to nine hours recommended for good health.

Participants were split into two groups: One made no changes to their lifestyle, but the other was instructed to extend the time they spent in bed each night by up to 90 minutes, and taught how to improve their sleep hygiene (that is, the everyday habits underpinning quality sleep).

For the next seven days, all participants kept sleep diaries, recorded what they ate, and wore wrist monitors to measure how long they slept.

Almost all of those in the sleep extension group increased the overall time they spent in bed, and half increased their sleep duration by a little over an hour on average. (Unsurprisingly, the group who made no changes to their lifestyle didn't change how much they slept.)

The food diaries revealed more sleep seemingly led to less sugar: the sleep extension group dropped their intake of free sugars (which generally means sugar added to products by food manufacturers) by almost 10g.

"The fact that extending sleep led to a reduction in intake of free sugars ... suggests that a simple change in lifestyle may really help people to consume healthier diets," said the study's principal investigator Dr Wendy Hall, from KCL's Department of Nutritional Sciences, in a statement.

Sidenote: while the sleep extenders increased their sleep duration, their sleep quality decreased (they slept longer, but not better) — perhaps because they needed more time to adjust to their new nighttime routines.

The study builds on earlier KCL research into how your sleep affects what you eat: a 2016 paper determined just one night of poor sleep subconsciously compels you to eat an average 385 calories more the next day.

(Which is a lot: The average person needs to eat about 2000 calories a day to maintain their weight, so 385 is a hefty percentage of that.)

The study's lead author Haya Al Khatib said the research emphasises the importance of sleep duration and quality for good health, including weight management.

"Our results also suggest that increasing time in bed for an hour or so longer may lead to healthier food choices," she said. "This further strengthens the link between short sleep and poorer quality diets that has already been observed by previous studies."